Natural gas, biogas, and methane hydrate are regarded as the most effective energy resources as global warming measures, and an interest in its use technique is increasing. Methane resource making use of its clean property attracts an attention as the next generation new organic resource and as a hydrogen resource for fuel cells.
As a process for producing hydrogen and aromatic hydrocarbons, such as benzene, from methane, one is known in which methane is reacted in the presence of a catalyst, such as Non-patent Publication 1. As the catalyst upon this, molybdenum supported on ZSM-5 is said to be effective.
However, even in the case of using these catalysts, there are problems that carbon is deposited in large amounts and that conversion of methane is low.
In order to improve the above-mentioned conventional technique, a lower hydrocarbon as the raw material gas (reaction gas) of the aromatic hydrocarbon and a hydrogen-containing gas or hydrogen gas as a gas (regeneration gas) for maintaining the catalytic activity or regenerating the catalytic activity are switched periodically and alternately to make contact reactions with the catalyst (e.g., Patent Publication 1). In this way, the catalytic contact reactions are conducted by alternating the raw material gas and the catalyst regeneration gas to maintain the catalytic reaction while suppressing the deterioration over time of the catalyst.